As more and more oil and gas, power generation, and mining industry projects surface to meet globular demands of an ever-expanding population, more piping systems must be planned, permitted and constructed to convey material. The methods of cutting metal pipes on construction sites (onsite) are lengthy, costly, and sometimes challenging in terms of meeting codes and standards in terms of quality and safety. The more productive and modern methods of cutting metal pipe are confined to local fabrication shops due to their physical size and immobility and are not used onsite.
The cuts that are performed onsite are done using conventional oxy-fuel or plasma cutting by hand, oxy fuel, plasma on a cumbersome carriage mounted on the pipe, and other mechanical methods such as grinding discs, toothed saws, and routers. These cuts require one or more skilled tradesmen, usually pipefitters and pipe welders, to understand piping systems, compute and calculate the cut profile, as well as measure and mark the cut. Performing the cut itself requires good operator skill and predetermined engineering quality standards need to be met. The degree of difficulty in performing the cut depends on the complexity of the joint and can range from a straight cut to a mitered and coped cut with weld preparation bevel. Some cuts are extremely challenging for a tradesman to compute and mark due to their eccentricity and complexity and are performed by trial and error by repeated test fitting. Further, a single pipe can have multiple cuts and holes further increasing the risk for incorrect cuts requiring repair and rework. Larger and longer pipes are very heavy and difficult to cut and the safety hazard is increased when handling. Further to all the above, cutting a single joint onsite using conventional methods can take 10 minutes up to 8 hours or more and will usually require more than one tradesman to perform cuts.
As will be readily appreciated, there is a need for improved efficiency, reduced cost, better quality, and safer methods for cutting pipe onsite. Despite this, there have been few attempts to improve pipe cutting onsite. One approach is disclosed in U.S. Patent Application 20100166513, which is directed to a mobile device for simultaneously cutting and chamfering a pipe, having a frame, at least one pipe collet-clamp attached to the frame and defining a principal axis, a split carriage rotatably mounted with respect to the frame about the axis and adjacent to the clamp(s), a router affixed to the split carriage and having a cutting-chamfering bit, and a drive motor for rotating the carriage. The router orbits around the pipe and simultaneously cuts it into two chamfered pipes. A method is also provided for cutting through a pipe and chamfering the cut ends thereof. This offers an improvement in safety and accuracy, however, much more can be done to provide a safe working environment, reduce man hours for tasks, improve efficiency, decrease human error, improve cut quality and increase safety. This method of cutting is slow with a router bit. Further it requires the tedious task of set up and removal for each and every cut.
U.S. Pat. No. 7,140,409 discloses a complete and portable tool for retaining round, square or other non-flat stock, especially pipes, in a secure fashion while cutting and related operations are performed thereon. The portable pipe cutting tool includes an adjustable work support, V-shaped trough, chain and tightening device, catch tray, left and right support arm bracket, mounting stand, and power tool having a base portion that, as a unit, secure the pipe in place while being cut, grooved or otherwise worked on, by an operator. The portable pipe cutting tool prevents sideways, upward, rotational or other movement of the pipe during such operations. Again, this offers an improvement in safety and accuracy, however, it much more can be done to provide a safe working environment, reduce man hours for tasks, improve efficiency, decrease human error, improve cut quality and increase safety. This tool does not allow for eccentric cuts, bevelling, coping or holes. Further, it requires the tedious task of set up and removal for each and every cut.
What is needed is a modular mobile Computer Numerical Control (CNC) pipe cutting station that is easy to transport on and off the site. The station would preferably be housed in an intermodal unit, allowing for transport by conventional means. It would preferably require little in the way of set-up and assembly on site. The intermodal unit would preferably include all safety equipment generally used in a machine shop and on industrial construction sites. It would also preferably include a power pipe conveying system that would transport the pipe into and out of the intermodular container without requiring human interaction until it is clamped by the CNC machine. It would also preferably include a rail system employing an power trolley and power hoist for lifting and transporting pipe into and out of the intermodular container. The station would preferably include computer hardware and software for the purpose of computer aided manufacturing to compute all the cuts needed for the CNC machine, as well as interface with warehousing software for stock control, scheduling and other significant warehousing controls and to locate and track pipe. The station would preferably employ fire protection, heating and ventilation systems, lighting, fume extraction, and dust collection systems, an eye wash station, a first aid kit, that meet codes, standards and best industry practices to allow workers and technicians to safely work inside the intermodular container. The station would preferably allow for physically marking and thus identifying the pipe that has been cut. This would greatly improve pipe tracking. Further, it would allow for identification of the individual who installs or stores the pipe.